Two “F” Words Worth Considering

OnMarch 6, 2014

Substitute teaching may seem like a strange hobby, but I enjoy it for more than one reason. The obvious one is that I like having a little extra money to spread around, both on myself and on various charities that I like to support. I have been so blessed by so many people in my life, and substitute teaching is one way that I can give back. I use my talents and training to encourage and help educate the next generation, to give teachers a much needed break when they need it, and the money I earn helps me feel freer to give to worthy causes.

But I have a more selfish reason than those for liking to substitute teach. I enjoy substitute teaching because I learn so much every time I walk into a new classroom. Most recently, I taught in a science class in which I found a stack of newspaper articles on my desk to hand out. I always try to read what the students are reading, even if they are doing quiet desk work, so that I can help them if they have questions. So I began reading the article entitled “Nuclear Fusion Project Takes Key Step in Lab Test.”

Nuclear fission

The article was enlightening in a number of ways. First of all, I got a much clearer idea of the differences between nuclear fusion and nuclear fission. Fission, which was used to develop the hydrogen bomb, splits the atoms apart. Fusion, the opposite from fission, merges hydrogen atoms. But more importantly, the differences between the processes opened my mind to nuclear energy as a positive alternative to fossil fuels. I have always been wary of nuclear energy as a good environmental choice because of my concern about radioactive waste, and also because of possible leaks at nuclear energy plants. But unlike fission, fusion would avoid the need for long-term storage of radioactive waste. So now I understand why there is so much interest in pursuing that energy form.

Secondly, fission uses uranium, which is an exhaustible source. Fusion, on the other hand, relies simply on the virtually unlimited supply of hydrogen, for example in seawater. So the worry about using up our fossil fuels is reduced greatly or eliminated. Another plus for nuclear energy is that neither fission nor fusion produces greenhouse gases that cause global warming.

The third difference between fission and fusion, however, dampens one’s optimism somewhat. Whereas fission produces a lot of energy for little energy input, fusion presently produces far less energy than it uses. The news article cites an online report by the journal Nature, in which scientists from the Lawrence Livermore National Laboratory near San Francisco describe results from two experiments done at the lab’s National Ignition Facility. In each trial, 192 laser beams briefly fired into a half-inch-long gold cylinder holding a tiny ball that contained the fuel.The energy from the lasers kicked off a process that compressed the ball by an amount similar to squeezing a basketball down into the size of a pea. But according to Debbie Callahan, the author of the paper describing the process, the results were far from the desirable goal of a process that produces more energy than it requires to operate.

But there is still hope. The scientists found that energy created by the fusion reaction was going back into the remaining fuel, a “bootstrapping” process that is key to boosting the energy output. Omar Hurricane, the lead author on the Nature paper says that “Seeing that kick in is quite exciting, and it does show that there is promise.” Fusion expert Robert McCrory of the University of Rochester agrees that the sign of bootstrapping is “really a wonderful result.”

Other scientists are working on a different approach to fusion power. This process uses magnetic fields to contain super-heated hydrogen fuel. In France, several nations are cooperating to build a huge experimental device to explore that approach.